Shredder paper feed mechanism and paper feeder

ABSTRACT

A shredder paper feed mechanism and paper feeder that, simply by setting a paper stack in the paper tray, enable a stack of document sheets to be fed to the shredder in an amount that matches the shredding capability of the shredder. This is done by using first and second rotating members equipped with claw members. The paper feed mechanism utilizes the transmitted rotary driving force of the shredder unit. The paper feed mechanism has a first rotating member having disc-shaped claw members with sharp portions for feeding the paper sheets, and rotation members; a transport roller; a second rotating member that limits the number of paper sheets that are fed onwards, and also has disc-shaped claw members with sharp portions for feeding the paper sheets, and rotation members; and a pressure roller that presses against the second rotating member to thereby grip and feed the paper sheets.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a shredder paper feed mechanism and paper feeder capable of feeding a stack of multiple paper sheets, particularly to a paper feed mechanism and paper feeder in which a stack of a number of paper sheets limited to a number the shredder can shred is fed by first and second rotating members equipped with claws that penetrate multiple paper sheets.

2. Description of the Prior Art

In order to prevent leakage of information, in recent years documents are not just discarded as they are, but are instead disposed of after first being cut into small pieces by a shredder or other such cutting machine. The performance of shredders has improved in recent years and more shredders are able to shred documents finely enough to make it impossible to piece the documents back together. However, there is still a problem of the number of sheets that can be shredded at one time being limited. Although feed mechanisms have been developed that separate the documents to be shredded and feed them one sheet at a time to the cutting mechanism, a problem still to be resolved is that of the jamming of the paper sheets that occurs when stacks of multiple numbers of paper sheets that can be shredded at one time are fed to the shredder, preventing shredding from being carried out with good efficiency.

To resolve the above problem, Japanese Patent Application No. 2006-145833, “Automatic paper feed mechanism and paper feeder”, discloses a mechanism that feeds a stack of multiple paper sheets. While the mechanism forcibly feeds a stack of a number of paper sheets that is restricted to the number of sheets the shredder is able to shred, it has a drawback in that the number of sheets fed by the powerful feeding force of the disc-shaped claw members exceeds the limit, producing a wedge-shaped stack that causes jamming and system downtime.

There has therefore been a need for the development of a paper feed mechanism and a paper feeder that limit the number of stacked paper sheets fed to the shredder so that the shredding capability of the shredder is not exceeded and which ensure smooth feeding of said sheet stacks to the shredder.

SUMMARY OF THE INVENTION

An object of the present invention is to resolve the above-mentioned problems by providing a shredder paper feed mechanism and paper feeder that, simply by setting the paper stack in the paper tray, enable a stack of document sheets to be fed to the shredder in an amount that is in accordance with the shredding capability of the shredder, by means of first and second rotating members equipped with claw members.

The present invention achieves the foregoing object by providing a shredder paper feed mechanism that utilizes transmission of a rotary driving force of a shredder unit in which paper sheets are shredded by intermeshed cutting blades, which paper feed mechanism comprises a first rotating member having disc-shaped claw members with sharp portions for feeding paper sheets, and rotation members; a transport roller that feeds a stack of paper sheets fed by the first rotating member; a second rotating member that limits the number of paper sheets in the stack fed by the transport roller and has disc-shaped claw members with sharp portions for feeding paper sheets, and rotation members; and a pressure roller in contact with the peripheral surface of the second rotating member to thereby grip and feed the paper sheets.

The sharp portions of the disc-shaped claw member are formed as prongs that are substantially perpendicular to the periphery of the disc-shaped claw member, or as claws formed on the periphery with the tips of the claws pointing in the direction of rotation.

The present invention also provides a paper feeder that utilizes transmission of a rotary driving force of a shredder unit in which paper sheets are shredded by intermeshed cutting blades, the paper feeder comprising a paper feeding tray having a floor with openings on which paper sheets to be shredded are set and held; a paper feed mechanism comprising disc-shaped claw members with sharp portions for feeding paper sheets, and rotation members, a transport roller that feeds a stack of paper sheets fed by the first rotating member, a second rotating member that limits the number of paper sheets in the stack fed by the transport roller and has disc-shaped claw members with sharp portions for feeding paper sheets, and rotation members, and a pressure roller in contact with the peripheral surface of the second rotating member to thereby grip and feed the paper sheets; and a gear unit comprised of a group of a plurality of gears engaged with at least one gear mounted on an end portion of the rotary shafts of the first rotating member, transport roller and second rotating member to transmit power from a drive source.

The paper feeder and paper feed mechanism described in the foregoing provide the following advantages.

1. Rotating members equipped with claw members provide two-stage separation of the paper sheets, enabling the number of sheets that are fed to be limited to the capacity of the shredder. Because the sheets are gripped for feeding between the second rotating member and the pressure roller, the sheets can be readily exited in stacked state, providing stable feeding of the sheets to the shredder unit. Moreover, the provision of the transport roller between the first and second rotating members equipped with claw members ensures a smooth paper feed.

2. Being brought into contact with the roller surfaces of the rotating members enables the stacks of paper sheets to be separated into stacks containing the maximum number of sheets the shredder is capable of shredding. The number of paper sheets that are fed can be controlled by the penetration of the sharp portions and the contact with the roller surface, enabling the sheets in a stack that is being fed to be limited to the number of sheets that can be shredded by the shredder.

3. The penetration of the sharp portions can be facilitated, and secure feeding of the paper sheets thus ensured, by forming claw members that point in the direction of rotation.

4. The driving force of the shredder unit is utilized, eliminating the need for another drive apparatus. Also, the gear arrangement facilitates the control of rotary shaft rotation, thereby providing efficient feeding of the paper sheets.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the paper feeder of the invention.

FIG. 2 is a perspective view of the first and second rotating members.

FIG. 3 is a side view of a disc-shaped claw member.

FIG. 4 is a side view of another disc-shaped claw member.

FIG. 5 is a sectional view of the gear engagement configuration in the paper feed mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The paper feed mechanism according to the present invention will now be explained with reference to an embodiment shown in the drawings, in which FIG. 1 shows a perspective view of the paper feeder of the invention, FIG. 2 shows a perspective view of the first and second rotating members, FIG. 3 is a side view of a disc-shaped claw member of the invention, FIG. 4 is a side view of another disc-shaped claw member, and FIG. 5 is a sectional view of the gear engagement configuration in the paper feed mechanism.

The paper feed mechanism 11 of the invention comprises a first rotating member 20, a transport roller 30, a second rotating member 40 and a pressure roller 60. The paper feeder 10 of the invention comprises a paper feed mechanism 11, a paper feeding tray 70 and a gear unit 80.

The first rotating member 20 is a substantially cylindrical member that separates the stack of documents in the paper feeding tray 70 into a paper stack 72 having a number of sheets that can be shredded by the shredder, and feeds onwards the sheets of paper thus separated. The first rotating member 20 comprises rotation members 22 affixed on a rotary shaft, and a disc-shaped claw member 50. In this embodiment, first rotating members 20 are provided at two locations. However, the provision of the first rotating member 20 is not limited to the number of locations used in this embodiment, but may be provided in one or a plurality of locations.

A rotation member 22 may be a roller member having a smooth, curved surface or, as shown in FIG. 1, a cylindrical member with a peripheral surface that is provided with serrations or protuberances 24.

The rotatably-mounted first rotating member 20 presses down on the paper stack 72 on the paper feeding tray 70, causing the tips of the sharp portions to penetrate the upper part of the stack 72. The penetrated portion of the stack 72 is thereby separated from the top of the document stack and fed to the transport roller 30.

The periphery of the disc-shaped claw member 50 has sharp portions constituted as prongs, in the case of sharp portions 52 a, or claws, in the case of sharp portions 52 b, that penetrate or dig into the paper stack 72, in which state the paper sheets from the stack 72 are fed. The disc-shaped claw member 50 may be provided at one or both ends of the rotation members 22.

As shown in FIGS. 3 and 4, the sharp portions 52 a are constituted by prongs formed to be substantially perpendicular with respect to the periphery of the disc-shaped claw member 50, or, in the case of sharp portions 52 b, by claws formed around the peripheral surface of the disc-shaped claw member 50 with the sharp ends pointing in the direction of rotation, so that in each ease the sharp portions can penetrate into the paper stack 72. Since the sharp portions 52 a are formed substantially perpendicularly, they can penetrate the paper stack 72 no matter what the angle is, ensuring that a set amount of the paper stack 72 is securely fed even when the paper stack 72 is an a disorderly state. Moreover, the size of the sharp portions 52 a and 52 b can be changed to match the number of paper sheets the shredder can shred.

As shown in FIG. 2, the rotating members can be formed as an assembly comprised of a plurality of rotation members 22 and a plurality of disc-shaped claw members 50. In this configuration, the number of sheets in the paper stack 72 penetrated by the sharp portions 52 a and 52 b is limited by the contact of the paper stack 72 with the peripheral surface or protuberances 24 of the rotation members 22. The amount of the paper stack 72 that is fed can be controlled by the height to which the sharp portions 52 a and 52 b project up from the periphery of the disc-shaped claw member 50.

Transport roller 30 is provided between the parallel first rotating member 20 and second rotating member 40 to transport the paper stack 72. From one to a plurality of transport rollers 30 can be provided in parallel. As in the case of the rotation members 22 and 42, transport roller 30 may be formed as a cylindrical member having a smooth surface, or as a cylindrical member having protuberances on its peripheral surface.

The second rotating member 40 separates the paper stack 72 transported by the transport roller 30 to limit the number of sheets in the stack to a number of sheets that can be shredded by the shredder, and feeds the sheets to the shredder unit. As in the case of the first rotating member 20 shown in FIG. 2, the second rotating member 40 is comprised of rotation members 42 and disc-shaped claw members 50. A rotation member 42 may be formed as a roller member having a smooth, curved surface or as a cylindrical member with a peripheral surface that is provided with serrations or protuberances 44.

The paper stack 72 is not fed as single sheets but as a plurality of overlapping sheets. However, it is also possible to feed single sheets. The number of sheets can be regulated by changing the ratio by which the disc-shaped claw members 50 or sharp portions 52 a and 52 b project from the periphery of the rotation members 22 and 42. It is also possible to use rotation members 22 and 42 and disc-shaped claw members 50 that are each of a different size. The sheet separation can be made to function more securely by making the width of the rotation members 42 of the second rotating member 40 and the sharp portions 52 a and 52 b projecting from the rotation members 42 less than that of the first rotating member 20.

As shown in FIG. 5, the pressure roller 60 is disposed on the lower side in opposition to the first and second rotating members, where it feeds the paper stack 72 by rotating in contact with the outer peripheral surface of the second rotating member 40. While the outer peripheral surface of the pressure roller 60 may be formed of synthetic resin or metal, desirably it is formed of a resilient material such as rubber. With a resilient outer peripheral surface, it feeds the paper stack 72 by pressing it vertically against the second rotating member 40, thereby obtaining a sure feeding operation and feeding force that equals or exceeds that provided by two rubber rollers or by a rubber roller and a rigid roller, and makes it possible to readily feed out the paper sheets in the stack form of the paper stack 72. An appropriate gripping force can be achieved by providing grooves on the outer peripheral surface of the pressure roller 60 that is contacted by the sharp portions 52 a and 52 b of the disc-shaped claw member 50.

The paper feeder 10 of the invention will now be explained. The paper feeder 10 comprises the paper feed mechanism 11, the paper feeding tray 70 and the gear unit 80. By incorporating the paper feeder 10 in a shredder apparatus having a main body and a paper feed outlet and mounting the feeder above the shredder unit, the feeder can be used as an automatic paper feeder. In this embodiment, the paper feeder uses the same drive source as the shredder, so there is no need for the paper feeder to have a separate, independent drive source.

The paper feeding tray 70 is the standby location for the documents and other sheets of paper comprising the stack 72 that is fed by the first rotating member 20. Because the feeding of the paper sheets is accomplished by using the disc-shaped claw members 50 of the first rotating member 20, the paper stack 72 may be set at any angle, so the upper surface of the main body of the shredder can be used as a horizontal paper feeding tray. The paper feeding tray 70 may be provided with openings in the face located where the disc-shaped claw members 50 rotate, to ensure the secure paper sheet feed rotation of the disc-shaped claw members 50 through penetration of the claw members into the paper stack. The floor of the paper feeding tray 70 could be jabbed if the disc-shaped claw members penetrate all the way to the back of the paper stack. Forming the openings in the paper feeding tray 70 ensures that the tray will not be scratched even if the stack is small and the sharp portions penetrate all the way through.

The paper feed mechanism 11 comprises a first rotating member 20, a transport roller 30, a second rotating member 40 and a pressure roller 60. The first and second rotating members 20 and 40 arc comprised of rotation members 22 and 42, respectively, and disc-shaped claw members 50.

The first rotating member 20, transport roller 30, second rotating member 40 and pressure roller 60 are mounted on the respective parallel rotary shafts 25, 35, 45 and 65 disposed between the sides of the feeder. Gears are mounted on the ends of the rotary shafts located on the side of the paper feeder via which driving power generated by a drive source is transmitted to the rotary shafts. Sheets of paper are forcibly fed using the sharp portions of the disc-shaped claw members 50 mounted on the rotary shafts.

Paper sheets from the top of the stack 72 placed on the paper feeding tray 70 are fed towards the shredder unit by the first rotating member 20. The sheets of the paper stack 72 penetrated by the sharp portions of the disc-shaped claw members 50 of the first rotating member 20 are fed to the transport roller 30, which limits the number of sheets to a low number. This is followed by a second stage in which the sheets of the paper stack 72 on the transport roller 30 are fed onwards by the second rotating member 40.

The gear unit 80, as shown in FIG. 1, comprises a group of multiple gears via which driving power from a drive source is transmitted to the paper feed mechanism. The rotational force of the drive source is transmitted by the engagement of the gear unit 80 with at least one of the gears mounted on the end of the rotary shafts 25, 35, 45 and 65. A configuration is used whereby the remaining rotary shafts are simultaneously rotated by using gears to engage with the rotary shaft to which the driving force is transmitted, and simultaneously the rollers in the paper feeder rotate. It is also possible to use a configuration in which the paper sheets are fed by the rotation of rotating members on freely rotatable rotary shafts that do not gears.

In the embodiment shown in FIG. 5, a first gear 26 provided on a rotary shaft 25 of a first rotating member and a second gear 36 provided on a rotary shaft 35 of a transport roller are engaged by a third gear 82, the gear unit is used to rotate one of the rotary shafts 25 and 35 while at the same time the other rotary shaft rotates. Also, second rotating member 40 rotates together with the rotation of the pressure roller 60 in the paper feeder driven by means of the gear unit 80.

It is also possible to use a configuration in which each of the rotary shafts 25, 35, 45 and 65 are rotated by engagement with each of the gears provided on the ends of the shafts.

The paper feeder 10 of the present invention is configured so that by setting a stack of paper on the paper feeding tray 70 and starting the operation of the shredder unit, driving force is transmitted to the gear unit 80 to rotate the rotary shafts filled with gears. This rotates the disc-shaped claw members 50 of the first and second rotating members 20 and 40, causing the sharp portions 52 a and 52 b to dig into the paper stack 72 and thereby feed a quantity of paper sheets that does not exceed a set amount towards the shredder unit. The paper feeder 10 may be equipped with a drive source to ensure the driving force of the paper feeder itself. The paper stack 72 can be fed whether the stack consists of one sheet or of a plurality of sheets.

As described in the foregoing, the feeding technology of the paper feed mechanism and paper feeder of the present invention uses a feed mechanism comprising a first rotating member 20, a transport roller 30 and a second rotating member 40. An assembly is used comprised of rotation members 22 and 42 and disc-shaped claw members 50 that limits the number of sheets that are fed in accordance with the shredding capability of the shredder, having a configuration that separates stack sheets and has a sheet width tolerance. The paper stack 72 is gripped and fed by the first rotating member and pressure roller and then fed by the second rotating member, forming a two-stage forced feed structure in which the paper sheets are penetrated twice by sharp portions. This enables the number of sheets in the stack fed to the shredder to be limited to the number that can be shredded by the shredder, and also enables stable paper feeding. 

1. A shredder paper feed mechanism that utilizes transmission of a rotary driving force of a shredder unit in which paper sheets arc shredded by intermeshed cutting blades, which paper feed mechanism comprises: a first rotating member having disc-shaped claw members with sharp portions for feeding paper sheets, and rotation members; a transport roller that feeds a stack of paper sheets fed by the first rotating member; a second rotating member that limits the number of paper sheets in the stack fed by the transport roller and has disc-shaped claw members with sharp portions for feeding paper sheets, and rotation members; and a pressure roller in contact with the peripheral surface of the second rotating member to thereby grip and feed the paper sheets.
 2. A paper feed mechanism according to claim 1, wherein the sharp portions of the disc-shaped claw member are formed substantially perpendicular to the periphery of the disc-shaped claw member.
 3. A paper feed mechanism according to claim 1, wherein the sharp portions of the disc-shaped claw member are formed on the periphery of the disc-shaped claw member with tips of the claws pointing in the direction of rotation.
 4. A shredder paper feeder that utilizes transmission of a rotary driving force of a shredder unit in which paper sheets are shredded by intermeshed cutting blades, the paper feeder comprising: a paper feeding tray having a floor with openings on which paper sheets to be shredded are set and held; a paper feed mechanism comprising disc-shaped claw members with sharp portions for feeding paper sheets, and rotation members, a transport roller that feeds a stack of paper sheets fed by the first rotating member, a second rotating member that limits the number of paper sheets in the stack fed by the transport roller and has disc-shaped claw members with sharp portions for feeding paper sheets, and rotation members, and a pressure roller in contact with the peripheral surface of the second rotating member to thereby grip and feed the paper sheets; and a gear unit comprised of a group of a plurality of gears engaged with at least one gear mounted on an end portion of the rotary shafts of the first rotating member, transport roller and second rotating member to transmit power from a drive source. 